The present invention relates to a door structure of a vehicle, in which an impact bar is provided in an inner space of a door body formed by a door inner panel and a door outer panel, the impact bar being configured to extend in a vehicle longitudinal direction and be joined to the door inner panel of the door body.
Conventionally, a structure shown in FIGS. 7 and 8 is known as an example of the above-described door structure of a vehicle. That is, a door body 83 is formed by a door inner panel 81 and a door outer panel 82, and the door inner panel 81 is, as shown in FIG. 7, formed integrally, through pressing, by a front side portion 81a, a lower side portion 81b, a rear side portion 81c, and a vertical wall portion 81d enclosed by the respective side portions 81a, 81b, 81c. Herein, at the vertical wall portion 81d are formed an opening portion 84 for arranging a door module and an opening portion 85 for arranging a sound speaker positioned in front of the opening portion 84. Further, an impact bar 87 is provided in an inner space 86 (see FIG. 8) of the above-described door body 83. The impact bar 87 is configured to extend in a vehicle longitudinal direction and be attached to the door inner panel 81.
The impact bar 87 is arranged such that it slants with its front being located at a higher level than its rear as shown in FIG. 7. A front end portion 87a of the impact bar 87 is formed as a flat portion 87b, which is formed in a flat shape. The flat portion 87b is joined by spot welding to a vertical face portion 81e, which extends in parallel to the vehicle longitudinal direction, of the front side portion 81a of the door inner panel 81, so that a joint face 88 is formed and the door rigidity in a vehicle head-on collision and a vehicle side collision is improved.
In the above-described conventional structure, the door rigidity in the vehicle collision (the vehicle head-on and side collisions) can be improved to a certain degree. However, since the above-described joint face 88 is arranged in parallel to an input direction of a collision load occurring in the vehicle head-on collision, the transmission performance of the vehicle-head-on collision load to the impact bar 87 may be so low that the vehicle-head-on collision load may not be received properly only at the impact bar 87 and therefore it may be necessary to provide another impact bar additionally.
Herein, Japanese Patent Laid-Open Publication No. 2007-216831 discloses a door structure of a vehicle which is substantially the same as the above-described conventional structure shown in FIGS. 7 and 8. Consequently, the door structure disclosed in the above-described patent document may have the same problem as that of the above-described conventional structure shown in FIGS. 7 and 8.